http://dspace-roma3.caspur.it:80 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Sat, 25 May 2013 12:28:03 GMT 2013-05-25T12:28:03Z http://dspace-roma3.caspur.it/image/logo_roma3.jpg http://dspace-roma3.caspur.it:80 http://hdl.handle.net/2307/220 <Title>On genuine cross-spectral density matrices</Title> <Authors>Gori, Franco; Ramírez-Sánchez, Victoria; Santarsiero, Massimo; Shirai, Tomohiro</Authors> <Issue Date>2009-08</Issue Date> <Is part of>Journal of Optics A: Pure and Applied Optics</Is part of> <Volume>11</Volume> <Pages>085706</Pages> <Abstract>For an electromagnetic stochastic beam, the choice of the mathematical structure of the cross-spectral density matrix is limited by the constraint of non-negative definiteness. We present a sufficient condition for building these matrices in such a way that this constraint is automatically satisfied. This allows us to put into evidence that electromagnetic beams can exhibit very peculiar correlation properties, some of which would not be encountered in scalar treatments. These results are illustrated by means of a number of examples.</Abstract> Fri, 31 Jul 2009 22:00:00 GMT http://hdl.handle.net/2307/220 2009-07-31T22:00:00Z http://hdl.handle.net/2307/219 <Title>Generation and characterization of spirally polarized fields</Title> <Authors>Ramírez-Sánchez, Victoria; Piquero, Gemma; Santarsiero, Massimo</Authors> <Issue Date>2009-06-29</Issue Date> <Is part of>Journal of Optics A: Pure and Applied Optics</Is part of> <Volume>11</Volume> <Pages>085708</Pages> <Abstract>Recently introduced global parameters for describing the polarization of a beam are used to characterize spirally polarized fields, which include as particular cases azimuthally and radially polarized fields. Theoretical predictions about such global parameters are experimentally confirmed by generating beams with spirally polarized transverse patterns, by means of two different procedures.</Abstract> Sun, 28 Jun 2009 22:00:00 GMT http://hdl.handle.net/2307/219 2009-06-28T22:00:00Z http://hdl.handle.net/2307/224 <Title>Synthesis of electromagnetic Schell-model sources</Title> <Authors>Santarsiero, Massimo; Borghi, Riccardo; Ramirez-Sanchez, Victoria</Authors> <Issue Date>2009-05-26</Issue Date> <Is part of>Journal of the Optical Society of America A-Optics, image science and vision</Is part of> <Volume>26</Volume> <Pages>1437-1443</Pages> <Abstract>A procedure for the synthesis of the most general electromagnetic Schell-model light source is proposed. It makes use of the generalized van Cittert-Zernike theorem to produce the electromagnetic sourcestarting from a primary spatially incoherent source, characterized by asuitable position-dependent polarization matrix. By resorting to the spectral decomposition of the polarization matrix, it is shown how such an incoherent source can be synthesized by using a Mach-Zehnderinterferometer, with suitable amplitude transmittances placed in its arms, fed by two mutually uncorrelated laser beams. Examples are givenfor the case of electromagnetic Gaussian Schell-model sources. (C) 2009 Optical Society of America</Abstract> Mon, 25 May 2009 22:00:00 GMT http://hdl.handle.net/2307/224 2009-05-25T22:00:00Z